Felt cleaner for paper mills



. Filed Oct. 1, 1955 Patented June 9, 1936 UNITED STAT FELT CLEANER FOR PAPER MILLS Lawrence L. Lapeyrouse, Chickasaw, Ala.

Application October 1, 1935, Serial No. 43,109

8v Claims.

This invention relates to devices for cleaning the endless felt or woolen blanket used between the press rolls of a paper making machine, where the felt belt acts as a conveyor for the wet sheet of paper and also as the medium through which water that is pressed out of the sheet passes onto the suction roll. These endless felts become dirty or filled up by the small fibres that adhere to them and they also require cleaning because a certain amount of rosin size, alum, starch, coloring matter and other ingredients are deposited on these felts.

The purpose of this invention, therefore, is

to provide means for cleaning these felts while the felts are in operation, thus not interfering with production.

The general practice in cleaning felts while in operation is to run the felt over a reciprocating vacuum chamber where a jet of water is first introduced to the felt and then this water is felt back. This friction Wears the felt as well as the shoe. The more water that is used, the greater the vacuum that is required and the grower the wear and tear on the felt.

One of the objects of my invention, therefore, is to provide means for cleaning the felt with little or no wear and to make it possible to use as much water or as great a vacuum as necessary.

A further object is to provide means whereby the felt will be "worked by opening and closing the meshes of the felt to thus disintegrate the dirt, dislodging it from the meshes or in the interstices of the felt and thus secure a more ready and efiective cleaning action.

Still another object is to provide a vacuum head having rollers disposed in series or at intervals across the'open face of the head and provide a water ejector over which the felt passes as it travels along said rollers, this water ejector being so formed as to provide a neutral section on each side of the slot through which the water is ejected so that by not having a vacuum at the point where the water is introduced to the felt, the water will be given a chance to wet water from being pulled away from the felt immediately after it is introduced.

A still further object of the invention is to form the rollers which extend across the vacu um head that certain rollers are transversely convex and the intermediate rollers are trans versely concave, this causing the flexing of the felt as it passes over the rollers and thus causing a working of the felt as before stated.

Other objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawing wherein: v

Figure 1 is a top plan view of a vacuum head constructed in accordance with my invention;

Figure 2 is a longitudinal sectional view of the head showing the manner in which the felt is flexed by the rollers;

Figure 3 is a section on the line 3-3 of Figure 1;

Figure 4 is a diagrammatic view illustrating the arrangement of the vacuum head with rela tion to the travel of the felt.

Referring to Figure 4, A, A designate the upper and lower press rolls between which the felt B passes. The felt B is guided over the usual felt rolls C between the two press rolls and the lower flight of the endless felt passes over the felt conditioner or cleaner which is my invention. The

paper D passes onto the upper flight of the felt a B and passes ofl as shown.

The felt cleaner includes a vacuum head designated it. This head or shoe as usual is much narrower than the felt B and is reciprocatecl transversely of the felt. This shoe is open along its upper face.

The neck ii is connected to any suitable air exhausting means which will create a vacuum within the head ill. The upper end of the head is formed by detachable rails if bolted at it to the body of the head and providing bearings at the junction of the rails if witl 'oe body if] for the journals of a series of rollers. The rollers it are transversely concave, as shown best in c Figure 1, and intermediate these rollers it are which extend upward and inward or, in other words, are beveled downwardly and outwardly,

these wall portions defining a slot l8 through which water is injected. This water injecting element It is connected to any suitable source of supply under any desired pressure, the inlet opening into this head being designated Hi. The greater portion of the head lies to one side of the water injecting element I6, as shown in Figure 2, and the felt B is supported upon a plurality of shaking rollers after the felt has passed the water supply element l6.

With a cleaner constructed in accordance with my invention, the felt will be pulled down by the vacuum onto the rollers 14 and I5, but inasmuch as these rollers will turn freely as the felt runs over them, there will be no friction and wear on the felt will be reduced to a minimum whereas in the ordinary felt conditioner or cleaner now in use, the felt is worn very rapidly due to the fact that the vacuum pulls the felt down over a stationary grill or grid having transverse bars. This drag over the stationary bars creates great friction and wears the felt. As the felt passes over the rollers I4 and I5, the felt is "worked and the meshes or interstices of the felt are opened up so that the dirt therein is disintegrated and is, therefore,more readily pulled out by the vacuum.

It will be seen from Figure 2 that the felt will first run over an evacuated portion of the head and over the two rollers at the entrance end of the head. These rolls act to first work the felt before the introduction of water, then the felt passes over the upper end of the element l6 and there is no vacuum at the point where the water I is introduced. This gives the water a chance to wet or soak the felt thoroughly before it is pulled past the neutral section or water introducing element. The felt is then again worked as it passes over the remainder of the rollers I4 and I to cause the dirt and clogging particles to be drawn off by the vacuum. If water were introduced upon the felt immediately that it enters the vacuum chamber ID, the water would be pulled away from the felt immediately, whereas by my construction, the felt is worked before it passes over the water ejecting means. The most important function of this invention is to clean the felt with the least possible wear by reducing friction. Hence the importance of so constructing the shoe or vacuum head so that the edges of the top surface will offer the least possible resistance to the forward movement of the felt.

While I have illustrated rollers l4 and I5 which are alternately concave and convex, I do not wish to be limited thereto as it is within the purview of my invention to provide rollers of any irregular design which will work the felt by opening and closing the interstices thereof. Neither do I wish to be limited to the exact details as illustrated, as these might be modified in many ways without departing from the spirit of the claims.

The vacuum head or shoe is reciprocated by any suitable means transversely of the felt 'as is usual in these conditioners. I have illustrated the shoe as being formed with a portion 20 engaged by a threaded shaft 2i shown in section in Figures 2 and 4, this screw being driven by any suitable means, as for instance, from the shaft of the roll A. When the shoe reaches the end of its travel adjacent one end of the felt, a trip (not shown) reverses the rotation of the screw and the shoe is, therefore, made to travel in the opposite direction. Thus the shoe travels back and forth across the belt but is stationary relative to the longitudinal movement of the belt. This method of traversing a shoe across a felt is wellknown and forms no part of my invention, therefore, I have not illustrated it in detail.

What is claimed is:

1. A felt cleaner for paper making machines including a vacuum head open upon one face, a series of rollers mounted in the head and extending across the open face thereof, and means for discharging water upon the felt.

2. A felt cleaner for paper making machines including a vacuum head open upon one face, a series of rollers mounted in the head and extending across the open face thereof, and means for discharging water upon the felt, said means being disposed intermediate the ends of the head.

3. A felt cleaner for paper making machines including a vacuum head open upon one face, a series of rollers mounted on the head and extending across the open face thereof, and a water ejecting element disposedwithin the head and extending transversely thereof and having a water ejecting slot discharging against the felt traveling over said rollers.

4. A felt cleaner for paper making machines including a vacuum head open upon one face, a series of rollers mounted on the head and extending across the open face thereof, and a water ejecting element disposed within the head and extending transversely thereof and having a water ejecting slot discharging against the felt traveling over said rollers, said element having relatively Wide beveled walls on each side of the slot.

5. A felt cleaner for paper making machines including a vacuum head open upon one face and a series of rollers mounted in the head and extending across the open face thereof, the rollers having a transversely irregular form.

6. A felt cleaner for paper making machines including a vacuum head open upon one face and a series of rollers mounted in the head and extending across the open face thereof, said rollers being so formed as to alternately bend the felt in one direction or the other to thus open the interstices of the felt.

7. A felt cleaner for paper making machines including a vacuum head open upon one face and a series of rollers mounted in the head and extending across the open face thereof, certain of said rollers being convex and intermediate rollers being transversely concave.

8. A felt cleaner for paper making machines including a vacuum head open upon one face and across which a felt is caused to travel, a series of rollers mounted in the head and extending across the upper face thereof to support the belt, the rollers being irregular in form to thus cause the belt to be flexed to thereby open the interstices of the belt, and transversely extending means disposed within the head for ejecting water against the face of the belt.

LAWRENCE L. LAPEYROUSE. 

